What Mercury's Ice Means For Alien Life In Our Solar System

The discovery of huge amounts of water ice and possible organic
compounds on the heat-blasted planet Mercury suggests that the
raw materials necessary for life as we know it may be common
throughout the solar system, researchers say.

Life on sun-scorched
Mercury remains an extreme longshot, the researchers
stressed, but the new results should still put a spring in the
step of astrobiologists around the world.

"The more we examine the
solar system, the more we realize it's a soggy place," Jim
Green, the director of NASA's Planetary Science Division, said
during a press conference today.

"And that's really quite exciting, because that means the amount
of water that we have here on Earth — that was not only inherent
when it was originally formed but probably brought here — that
water and other volatiles were brought to many other places in
the solar system," Green added. "So it really bodes well for us
to continue on the exploration, following the water and its signs
throughout the solar system." [Latest
Mercury Photos from Messenger]

Organics, too?

The observations by Messenger, which has been orbiting Mercury
since March 2011, provide compelling evidence that reflective
patches first spotted near the planet's poles by the Arecibo
radio telescope in Puerto Rico two decades ago
are indeed water ice, researchers said.

In the coldest parts of Mercury — permanently shadowed regions
where temperatures drop to perhaps minus 370 degrees Fahrenheit
(minus 223 degrees Celsius) — this ice can lie bare and exposed.
But Messenger's data also show that much more frozen water is
found in slightly warmer areas, buried beneath a strange dark
material that acts as an insulator.

This dark stuff is likely a mixture of complex organic compounds,
the carbon-containing building blocks of life as we know it,
researchers said during Thursday's news conference.

"This organic material may be the same type of organic material
that ultimately gave rise to life on Earth," said Messenger
participating scientist David Paige of UCLA.

Helping scientists read the book of life

Mercury probably acquired much of its water and organic material
the same way Earth did, researchers said — via comet impacts and
asteroid strikes. Ice and organics are common on the frigid
bodies in the solar system's outer reaches.

"There's a lot of water out there, as there is a lot of water
around other stars, but at substantial distance," said Messenger
principal investigator Sean Solomon, of Columbia University's
Lamont-Doherty Earth Observatory.

With its ultra-thin atmosphere and proximity to the sun, Mercury
is probably not a good bet to host life as we know it. But
finding ice and organics there should still inform the hunt for
organisms beyond Earth and aid scientists' quest to learn more
about how life took root on our planet.

"The history of life begins with the delivery to some home object
of water and of the building blocks, the organic building blocks,
that must undergo some kind of chemistry, which we still don't
understand on our own planet," Solomon said.

"And so Mercury is becoming an object of astrobiological
interest, where it wasn't much of one before," Solomon added.
"That's not say to say that we expect to find any lifeforms — I
don't think anybody on this table does — but in terms of the book
of life, there are some early chapters, and Mercury may indeed
inform us about what's in those chapters."